Traffic lights.
 

Since starting on the Hypermiling drug I have discovered something about lots of traffic lights here in Scotland. Lights on the main drag are geared to through traffic, and don't change very often for crossing/joining traffic. They have sensors set into the road, within 10 metres of the stop line, and until you make that sensor the light stays on red. Without making the sensor the lights will change, but it can be once every 5-7 minutes, depending on the time of day. It kind of spoils trying to time the lights.

http://i.imgur.com/Rfvnxtt.jpg

It's not always easy, but the trick is to get someone else in front of you to change the light! :D

That's the problem with these lights. a couple of cars an hour is a busy spell. The good thing is, once you stop in the box the lights start to change, so there is no advantage in switching off. The next set of lights along from those are peculiar. The main drag goes amber, red, then, if there is nothing waiting to come out the side road, goes straight back to red/amber, green. First time I saw it I thought my eyes were playing trick. Green, Red to Green in about 3 seconds!

I have read about bikers fitting magnets to their bikes so that the sensors see them as a car and change sooner. unfortunately fitting a magnet to a car doesn't do much.

Most traffic lights here is sweden work well with this system. At night on a quite road you can just keep driving at normal speeds even if it is red and 9 times out of 10 it will go green just before you need to slam your brakes on (so as not to run through a red light).

If you know you're going to stop, you key off well before the stop and glide on in. Bump start when you're pulling into the box, and you're golden- just pull on out with the green. :thumbup:

That's a great idea. Lights here don't have sensors as you approach, though temporary lights at roadworks usually have camera on top, so they can see vehicles approaching and change appropriately.

We used to have some at a quarry that I worked at, we discovered that those were IR cameras and that you could encourage them to change by flashing your full beams.

I tried it out on the roads and got mixed results, so it might depend on how they are positioned or it only works on a few particular cameras.

I found that too. As you approach you stick your full beam on and they see you sooner.